Today, the typical home has a wide variety of electrical and electronic devices performing many diverse and unrelated functions. To the extent if any that these devices are interconnected or connect to the outside world, the connections at most form isolated islands of connection or communication.
For example, if the homeowner has a television and a video cassette recorder, these elements connect to each other, to the AC power grid and to a source of analog video signals, such as an antenna or a cable television link. The television set may also connect to an output from a video game. Typically, these connections are analog.
The home-owner also will have an audio system, often comprising interconnected components such as an amplifier, a compact disk (CD) player and a tape recorder. A tuner connects to an antenna or other RF source, and the amplifier provides connections to one or more sets of speakers. In most installations, the audio system is connected together by various analog wiring separate from that used to interconnect the video system components.
There have been some proposals for interconnecting in-house video systems. For example, U.S. Pat. No. 5,010,399 to Goodman et al. discloses a system for transmitting signals between video components over residential telephone wiring, to enable one VCR to supply television signals to multiple television receivers in different rooms. Control signals also are sent over the telephone wiring to control the VCR. The Goodman system provides communications mainly for video components. U.S. Pat. No. 5,130,793 to Bordry et al. discloses a tapping technique for such a system, to enable baseband transmission of audio and video signals over twisted-pair wiring. These in-house video communication systems utilize analog communications and provide only limited communications capabilities. They also do not provide communications to the outside world.
U.S. Pat. No. 5,708,961 to Hylton et al. discloses a digital video system, providing wireless distribution of selected broadband programs from a public network to individual terminals and associated TVs within the premises. There is a suggestion that one of the video terminals might provide an interface to a personal computer (PC), to enable the PC to communicate via the digital network.
Today, telephone station sets or other telephone equipment separately connects to an analog or integrated services digital network (ISDN) telephone line. Typically, the telephone line does not interconnect to the video or audio equipment.
Most appliances in the home stand alone. For example, the heating and air-conditioning system, the hot water heater, the stove, the microwave, the refrigerator, etc. all have connections to power, but not to any type of central control. Some homes do have alarm systems, and some such systems will monitor some internal conditions or appliances, like the temperature maintained by the heating and air-conditioning system; but these systems only provide internal alert signals and/or communications to some outside agency, typically over the telephone line. Again, the system entails wiring that is separate from that used for other purposes, such as audio and video entertainment.
Many individuals now have their own personal computers (PCs), and today, the typical PC includes some type of modem for communication. Typically, the modem provides a data link through either the telephone line or the cable television network to enable access to the public Internet. Although there have been some proposals to interconnect the PC to alarm systems, appliances and/or video and audio components, such interconnections have not been particularly successful. Often, the interconnection has been rather limited, for example, to just allow the PC to control an appliance or in-home lighting or just to allow the PC to monitor the alarm system. In other proposals, the PC interconnection provides more comprehensive communications, but the interconnection has been overly complex and expensive. Interconnection to a television, for example, typically requires a set-top terminal or adapter with almost as much hardware as in the PC itself.
Also, with the increasing popularity of PCs, many people now find that they have more than one PC in their homes. Many of these individuals also are finding reasons to interconnect their PCs, to share certain resources such as a high-speed Internet access link or a printer or to exchange data for various purposes. A number of products have recently reached the market to allow in-home networking. However, these products have focused entirely on the PC-to-PC communications. Most of these products essentially provide a local area network (LAN) in the home, which is some form of scaled down network similar to those used in commercial enterprises. For example, Tut Systems offers a line of home networking product under the name HomeRun. A network constructed from the products provides a 10 Mb/s LAN over a single pair of twisted wires. However, the LAN provides data connections only for computers and related peripheral equipment. As such, there is no communication with many of the other systems and appliances in the home. Other systems, such as the audio and video systems, remain as separate analog only systems with no communication over the in-house LAN. Also, existing home data network products provide little or no outside access, except possibly through a shared computer resource such as a modem or the like within one of the PCs.
As shown by the above discussion, the existing in-home systems have remained isolated, either as individual units or small collections of interconnected units. There has not been a unified interconnection strategy. Also, access by each system to wide area communications, external to the premises, has been dedicated to one external network. The video system components receive television programming from a cable or antenna carrying channels of a set of predetermined frequencies. Audio system components similarly receive radio programming from an antenna carrying channels of another set of predetermined frequencies. Alarm systems communicate via ISDN or POTS type telephone lines and the public switched telephone network (PSTN). The PC may use a telephone line, ISDN, DSL or cable modem, but typically PC communications for one user access only one such external media.
A need therefore exists for a home network product that provides a simple common interface usable by a wide range of systems and appliances within the premises. Such a network should offer digital communication capabilities to the different devices coupled to the network. Also, the network should provide access to two or more communications media connected to public network facilities. Preferably, one or more of the outside network connections should provide broadband digital capabilities. It is desirable that the in-home network enables virtually all devices to selectively access any or all of the external communication resources.